Joint Seminar: Ice cores and climate: rapid climate change and glacial cycles

The last few hundred thousand years are critical for understanding the working of the Earth System because they show a wide range of climates under a geography similar to the present.  Ice cores are an important palaeorecord because they record different aspects of the atmosphere (including trace gas concentrations) rather directly.  Over recent decades, ice cores have provided several insights that have shaped the research agenda, and informed discussions about future climate change. 

For example, it is only from ice cores that we can be sure how much greenhouse gas concentrations (CO2, CH4, N2O) have risen above their natural level in the last two centuries.  Studies of Greenland ice cores have shown that very rapid climate changes (several degrees in a few decades) can occur, probably due to changes in ocean heat transport. The signal seen in Antarctic ice cores confirms that this is indeed the probable mechanism for these rapid changes, which represent the largest source of climate variability during recent glacial periods. 

The European Project for Ice Coring in Antarctica (EPICA) is a consortium of scientists from 10 European nations that has recently completed two ice cores to bedrock.  One of them extends the ice core record back to 800,000 years ago.  This nearly doubles the time span covered by ice cores.  The record confirms that the interglacial-glacial periodicity of 100,000 years prevailed throughout this period, but with much weaker interglacial amplitudes in the early half of the record. It also confirms the close relationship between different parameters. CO2 and Antarctic temperature show a particularly close relationship, with low concentrations in cold periods, and higher concentrations in warmer periods.  Chemical records indicate how other parts of the Earth System may have behaved.  Taken together these results present a compilation of the behaviour of the earth that challenges palaeoclimatologists and Earth System modellers towards better understanding of the system.




13:30 Uhr


Bundesstr. 53, room 022/023


Eric Wolff, British Antarctic Survey, Cambridge, UK


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